<?php
class Student {
    private $surname;
    private $first_name;
    private $emails;
    private $grades;
    private $status;
    function __construct($surname,$first_name,$status)
{
    $this->$surname =$surname;
    $this->first_name = $first_name; 
    $this->emails = array(); 
    $this->grades = array();
    $this->status = $status;
}
    function add_email($which, $address) 
{ 
$this->emails[$which] = $address; 
} 
    function add_grade($grade) 
{ 
$this->grades[] = $grade; 
} 
    function average() 
 { 
 $total = 0; 
 foreach ($this->grades as $value) 
 $total += $value; 
 return $total / count($this->grades); 
 }

    function add_status($status){
$this->$status=$status;
 }
 function toString() 
 { 
 $result = $this->first_name . ' ' . $this->surname . ''. $this->status; 
 $result .= ' (' . $this->average() . ")\n"; 
 foreach ($this->emails as $which => $what) 
 $result .= $which . ': ' . $what . "\n"; 
 $result .= "\n"; 
 return '<pre>' . $result . '</pre>'; 
}
}
